Closure having a mandrel for a container

ABSTRACT

The invention relates to a method for producing a mandrel ( 1 ) for a container closure, characterized in that the mandrel ( 1 ) is first produced in an injection moulding process and separately therefrom at least one seal ( 2 ) is produced and thereafter fixed on the mandrel ( 1 ), or that the mandrel ( 1 ) is first produced in an injection moulding tool by injection moulding process and at least one seal ( 2 ) is produced from a different material in the same injection moulding tool, likewise in an injection moulding process.

The invention relates to a container closure with a pin, the pin, and amethod of making such a pin according to the features of the preamblesof the independent claims.

A container closure for a container having a so-called push-pull closureis known from EP 1 737 743 [US 2008/0067721], and the container closure(reference numeral 2) has in the sleeve part (reference numeral 1) adisplaceable pin (reference numeral 9) with a tearing and piercingdevice (reference numeral 10).

This displaceably mounted pin must be sealed against its externalsurroundings (in the case of EP 1 737 74) for example relative to theadditional chamber (reference numeral 8) or a chamber formed by a safetycap (reference numeral 15).

No sealing measures are known from this prior art.

Therefore the object of the invention is to provide a closure having apin for a container, or the pin itself, by which the sealing measuresare implemented. Moreover a method should be provided of making such apin for a closure for a container that is for sealing purposes.

For this purpose according to the invention the pin (also referred to asthe piercing spike) viewed along its axial length has at least onecircumferential seal, preferably has two circumferential seals disposedat a defined distance relative to one another.

The seal, preferably the at least two seals, bear against the housing ofthe closure for the container. As a result it is possible for the pin tobe movable in the housing and for the chamber filled with a material tobe sealed in its first position against the external surroundings. Ifthe pin is displaced by manual action, the seal, preferably both seals,the opening in the housing, which hitherto has been closed by the sealand the pin, is exposed. As a result for example a liquid that haspreviously been mixed with the material can be removed from thecontainer (for example by drinking) via the closure of the container.

Furthermore two alternative methods are specified of making such a pinfor a container closure.

On the one hand according to the invention first of all the pin itselfis produced from the suitable plastic material by injection molding andseparately therefrom at least one seal, preferably both seals, and thenis secured on the pin.

As an alternative to this it is conceivable that first of all the pin isagain produced from a suitable plastic material by injection molding inan injection mold, and then in the same injection mold the seal,preferably both seals, is produced from a different material from thatof the pin, also by injection molding.

The two variants for configuration of a pin for a container closure thathave been produced in different ways are illustrated in the two FIGS. 1and 2 and are explained below.

To the extent that details are shown, FIG. 1 shows a pin for a containerclosure. The closure is for a container forming a chamber filled with amaterial, and a pin 1 is movable in the housing and can pierce a coverof an opening in the housing so that the material from the chamber inthe housing can enter the container. Purely by way of example, for sucha closure reference may be made to EP 1 737 743. However, the use of theclosure according to the invention as described here as well as the useof the pin and also the method of making such a pin are in no wayrestricted to this prior art, so that the pin can also be used forcomparable configurations of such a closure for a container.

The pin 1 that is illustrated in FIG. 1 has a plate-shaped upper end,and the lower end is cut off in FIG. 1 and is not illustrated orexplained in greater detail. The lower region is in any case configuredin such a way that it is suitable for piercing the cover of the openingin the housing. At least one seal 2 is located axially between the upperand lower ends of the pin 1, and in the embodiment of FIG. 1 two seals 2and 3 are provided that are spaced apart from one another. The two seals2 and 3 can have the same shapes and/or can be made of the samematerial. In the embodiment according to FIG. 1 the seal 2 has a smallerdiameter than the seal 3, the opposite also being conceivable. It isimportant that the seal 2, in particular the two seals 2 and 3, is/aredesigned so as to be adapted to the shape of the pin 1 and not onlyrelative to the pin 1 that they engage, but also fit with the housing ofthe closure of the container and thus effect the required sealing effectin one position of the pin 1 with respect to the housing of the closure.

In the embodiment of FIG. 1, first of all the pin 1 is produced byinjection molding in an injection mold. Then at least the second seal 2,preferably the two seals 2 and 3, is/are also produced by aninjection-molding process in the same injection mold. This requires atwo-part tool and a two-step injection-molding process. The choice ofthe material for the pin 1 on the one hand and the seal 2, or the twoseals 2 and 3 on the other hand, depends upon the purpose for which theyare to be used. In particular the pin 1 is made of a hard plasticmaterial in order to be able to withstand the pressure forces acting onit during axial displacement. The material for the seal 2 depends uponthe sealing function.

FIG. 2 shows in principle the same construction of the pin 1 as in FIG.1, but with the difference that the pin 1 is produced separately fromthe seal 2, in particular the two seals 2 and 3. If the parts aremanufactured separately from each other, they can then be assembled. Inthis case the contact shapes of the seal 2 are generally complementaryto the shape of the pin 1. For example it may be mentioned here that oneof the two seals 2 and 3 (or also both seals 2 and 3) is an O-ring (ofround cross-section) and the shape in the pin 1 is a circumferentialgroove of approximately semicircular cross-section. These contact shapesare only given by way of example and could of course also be designeddifferently.

These seals can for example be designed as separate components and canbe assembled after the production of the one- or two-part pin. Suchseparate components are for example O-rings or the like. In thisconnection the pin has for example a circumferential groove into whichthe seal is fitted by positive engagement.

However, the radially circumferential seal can also be produced byinjection molding. In this case it is conceivable that the radiallycircumferential seal is produced, in particular injection molded, in thesame tool in a two-part method together with the production of the pin.Because of the different functions different requirements applied to thepin and the seal, they are preferably made of different materials, inparticular plastic materials. The pin itself is made of a hard plasticmaterial that ensures that the forces acting on it (piercing forces) canbe transmitted. Since the seal must perform a sealing function, it ismade of a resiliently deformable plastic material.

Whereas on the one hand it is conceivable that the pin and the seal,preferably the two seals, are produced in the same injection mold, it isalso conceivable that first of all the pin is produced in a firstinjection mold and then the already produced pin is placed in a furthertool and then is overmolded with the preferably resiliently deformableplastic material.

As a rule, as in the above-described prior art, the pin is in two parts,and at least one of the two parts of the pin has one seal. Furthermoreit is conceivable that on one part of the two-part pin there are twoseals and then in the second part no seal is present, and it is alsoconceivable that each part of the pin has its own seal. Alternativelythe pin can be configured in one piece and can have the seal.

1. A closure for a container having a housing forming with the closure achamber filled with a material, a pin being movable in the housing andable to pierce a cover of an opening in the housing so that the materialfrom the chamber in the housing can exit the container, wherein the pinhas along its axial length at least one seal that is supported on thehousing.
 2. The closure according to claim 1, wherein the pin has alongits axial length two seals that bear against the housing.
 3. The closureaccording to claim 1, wherein the seal is a component that can be fixedseparately on the pin.
 4. The closure according to claim 1, wherein theseal is integral with the pin.
 5. A pin for a container closure, whereinthe pin has at least one seal along its axial length.
 6. A pin accordingto claim 5, wherein the pin has two seals along its axial length.
 7. Thepin according to claim 5, wherein the seal is a component that can befixed separately on the pin.
 8. The pin according to claim 5, whereinthe seal is unitary with the pin.
 9. A method of making a pin for acontainer closure, the method comprising the steps of: first of allmaking the pin by injection molding and separately therefrom making atleast one seal and then fixing the made seal on the pin.
 10. The methodof making a pin for a container closure according to claim 9, whereinfirst of all the pin is produced by injection molding in an injectionmold and in the same injection mold at least one seal is produced from adifferent material also by injection molding.